Microbiology Study Questions (Everything)
A method for sterilizing milk, called _____ temperature treatment, uses 134° C for 1 to 2 seconds.
ultra high
All of the following are methods of disinfection or sterilization, except: a. gamma radiation. b. dry oven. c. lyophilization. d. triclosan. e. ethanol.
C
iodophors include: a. chloramines b. betadine c. tincture of iodine d. alcohols e. chlorhexidine
B
ssRNA virus a. herpesvirus b. HIV c. poliovirus
C
_____ filters are widely used to provide a flow of sterile air to hospital rooms.
...
_____ radiation excites atoms to a higher energy state within molecules such as DNA that then leads to the formation of pyrimidine dimers.
...
__________ or steam sterilization is the process by which steam is heated under pressure to sterilize objects.
...
Vials of microorganisms that undergo the freeze-drying process called _____ will remain preserved and viable for years.
....
A(n) _______ is a section of prokaryotic DNA that contains one or more genes along with a corresponding operator to control transcription. a. operon b. promoter c. transposon d. repressor
A
Alcohols are more effective at inactivating enveloped viruses than naked viruses. a. true b. false
A
All viruses require the use of host cell ribosomes and host cell tRNA to translate viral mRNA into viral proteins. a. true b. false
A
Aniline dyes like crystal violet have antimicrobial activity particularly against gram positive bacteria and some fungi. a. true b. false
A
Chlorine dioxide and ethylene oxide are gaseous sterilants. a. true b. false
A
DNA is the blueprint that indicates which kinds of proteins to make and how to make them. a. true b. false
A
DNA photolyase is a light-sensitive enzyme able to repair DNA damaged by ultraviolet radiation. a. true b. false
A
Disinfection of beverages, such as apple juice, milk, and wine, is optimally achieved by: a. pasteurization b. chlorination c. moist heat autoclave d. filtration e. boiling water
A
Dry heat: a. is less efficient than moist heat b. cannot sterilize c. includes tyndallization d. is used in devices called autoclaves e. will sterilize at 120C for 15 minutes
A
Ethylene oxide is: a. sporicidal. b. only effective with high heat. c. the active agent in household bleach. d. used as an antiseptic against anaerobes. e. a halogen.
A
Filtration is an effective method to remove microbes from air and liquids. a. true b. false
A
HEPA filters are used to remove microbes from: a. air b. liquids c. human tissues d. medical instruments e. all of the choices are correct
A
According to Chargaff's rule, which of the following statements about double-stranded DNA is NOT true? a. A=T and C=G b. A+G=T+C c. A+T=C+G
C
Random change in the DNA arising from errors in replication that occur without a known cause a. spontaneous mutation b. induced mutation c. substitution mutation d. frameshift mutation
A
Random fragments of disintegrating host DNA are taken up by the phage during assembly a. generalized transduction b. specialized transduction
A
The DNA replication machinery is assembled at the replication fork. a. true b. false
A
The lac operon is normally in an off mode and does not initiate enzyme synthesis when the appropriate substrate is absent. a. true b. false
A
The minimum sterilizing conditions in a steam autoclave are: a. 121° C at 15 psi for 15 minutes. b. 63° C for 30 minutes. c. 160° C for 2 hours. d. 71.6° C for 15 seconds. e. 100° C for 30 minutes.
A
The presence of organic matter such as saliva and pus can interfere with the actions of disinfectants. a. true b. false
A
The sterilizing gas used in a special chamber is: a. ethylene oxide b. iodophor c. glutaraldehyde d. formaldehyde e. chlorine dioxide
A
The use of a physical or chemical process to destroy vegetative pathogens on inanimate objects is: a. disinfection b. sterilization c. antisepsis d. sanitization e. degermation
A
Transcribed version of a structural gene or genes in DNA a. messenger RNA b. transfer RNA c. ribosomal RNA
A
When a control agent targets the metabolic processes of microbial cells, active younger cells typically die more rapidly than older cells. True a. true b. false
A
When one bacterium donates DNA to another bacterium, a type of genetic recombination known as _________ has occurred. a. horizontal gene transfer b. transportation c. sexual reproduction d. vertical gene transfer
A
Which control method would not be a suitable choice for killing Mycobacteria in a capped culture tube? a. ultraviolet (germicidal) light b. gamma rays c. 121° C at 15 psi for 15 minutes d. 160C for 2 hours e. all of the choices are correct
A
Which of the following chemicals is a disinfectant for soft contact lenses? a. hydrogen peroxide b. alcohol c. hexachlorophene d. glutaraldehyde e. hypochorites
A
_____ heat is more rapidly effective and efficient compared to _____ heat. a. moist, dry b. dry, moist
A
dsDNA virus a. herpesvirus b. HIV c. poliovirus
A
microbiological contaminants are best described as: a. unwanted microbes present on or in a substance b. any and all microbes present on or in a substance. c. pathogenic microbes present on or in a substance. d. vegetative microbes present on or in a substance. e. None of the choices are correct.
A
which of the following does not contain a heavy metal? a. tincture of iodine b. merthiolate c. silver nitrate solutions d. zinc e. mercurochrome
A
Chlorine compounds remain stable and effective in the presence of excess organic matter. a. true b. false
B
Codons are found on tRNA, and anticodons are found on mRNA. a. true b. false
B
A microorganism that is not motile and has stopped metabolizing could be considered dead. a. true b. false
B
All of the following are correct about food irradiation, except: a. food is not made radioactive by the process. b. the World Health Organization does not endorse this process. c. it is approved in the U.S. for beef, chicken, and pork. d. it can lead to a longer shelf life for the irradiated food. e. no irradiated food can be sold without clear labeling.
B
All of the following are correct about iodophors, except: a. they are complexes of iodine and a neutral polymer. b. this formulation allows a quick release of free iodine. c. this formulation increases its penetration. d. it is less prone to staining or irritating tissue. e. a common iodophor is Betadine.
B
All of the following are correct about the autoclave, except: a. it is important not to overload the chamber. b. it is effective for sterilizing powders, oils, and waxy substances. c. the duration of the process depends on how full the chamber is. d. it is the temperature that kills the microbes, not the pressure by itself. e. sterilization is achieved when steam condenses against the objects in the chamber and raises their temperatures.
B
Bacteriocidal agents are sterilants. a. true b. false
B
Bacteriostatic agents kill bacterial cells. a. true b. false
B
Commercial products containing which types of chemicals are more effective at killing microorganisms? a. bacteriostatic b. bacteriocidal c. carbohydrate d. lead e. None of these are correct.
B
Contains the anticodon and an amino acid binding site a. messenger RNA b. transfer RNA c. ribosomal RNA
B
DNA replication is said to be a. dispersive b. semi-conservative c. conservative d. liberal e. inconclusive
B
Genetic ______ and the variations they produce result in population changes and thus, evolution. a. regulation b. mutation c. operons d. translations
B
Highly specific part of the host genome is regularly incorporated into the virus a. generalized transduction b. specialized transduction
B
In a repressible operon, excess product acts as a corepressor to increase transcription of the operon. a. true b. false
B
Isopropyl alcohol wiped across a skin site can sterilize it. a. true b. false
B
Most microbial contaminants of food are killed at freezing temperatures. a. true b. false
B
Result from exposure to known mutagens, which are primarily physical or chemical agents that damage DNA a. spontaneous mutation b. induced mutation c. substitution mutation d. frameshift mutation
B
Short lengths of RNA called ________ have the ability to control the expression of certain genes. a. messenger RNA (mRNA) b. small interfering RNA (siRNA) c. ribosomal RNA (rRNA) d. transfer RNA (tRNA)
B
The acceptance by a bacterial cell of small DNA fragments from the surrounding environment is termed ________. a. transposition b. transformation c. conjugation d. transduction
B
The compound that is an organic base containing chlorine and two phenolic rings and is used increasingly for hand scrubbing, neonatal washes, wound degerming, and prepping surgical skin sites is: a. carbolic acid b. chlorhexidine c. triclosan d. formalin e. quaternary ammonium compounds
B
The easiest microbial forms to kill or inhibit are: a. naked viruses b. vegetative bacteria and fungi c. endospores d. protozoan cysts e. mycobacterium and staphylococcus
B
The newly-synthesized strand of DNA has exactly the same base sequence as that of its template strand. a. true b. false
B
The process that destroys or removes all microorganisms and microbial forms including bacterial endospores is: a. disinfection b. sterilization c. antisepsis d. sanitization e. degermation
B
The shortest time required to kill all the microbes in a sample at a specified temperature is called the: a. thermal death point (TDP) b. thermal death time (TDT) c. sporicidal time d. death phase point e. none of the choices are correct
B
Transformation is a mode of genetic recombination in which a plasmid is transferred from a donor cell to a recipient cell via a direct connection. a. true b. false
B
Using toilet bowl cleaner and nonionizing radiation to inanimate surfaces only removes or kills vegetative bacteria. The term that best describes this action is: a. sterilization b. disinfection c. antisepsis d. degermation e. none of these are correct
B
Which common hospital pathogen is able to grow abundantly in soap dishes? a. Escherichia coli b. Pseudomonas c. Hemophilus influenzae d. Mycobacteria tuberculosis e. Salmonella
B
Which of the following is being used to replace hypochlorites in treating water because of the possibility of cancer-causing substances being produced? a. hydrogen peroxide b. chloramines c. fluorine d. quaternary ammonium compounds e. sodium iodine
B
retrovirus a. herpesvirus b. HIV c. poliovirus
B
the ______ is the sum total of genetic material in a cell a. heredity b. genome c. genetics d. phenotype
B
All of the following pertain to hypochlorites, except: a. release hypochlorous acid in solution b. cause denaturation of enzymes c. found in iodophors d. used to disinfect dairy, restaurant, and medical equipment e. found in common household bleach
C
Changing of single base in the DNA code that may result in the placement of a different amino acid a. spontaneous mutation b. induced mutation c. substitution mutation d. frameshift mutation
C
Forms a complex cellular structure that contributes to the process of translation a. messenger RNA b. transfer RNA c. ribosomal RNA
C
The chemical agent that produces highly reactive hydroxyl-free radicals and also decomposes to O2 gas is: a. cidex b. cationic detergents c. hydrogen peroxide d. chlorhexidine e. iodophors
C
The use of chemical agents directly on exposed body surfaces to destroy or inhibit vegetative pathogens is: a. disinfection b. sterilization c. antisepsis d. sanitization e. degermation
C
Which is correct regarding the rate of microbial death? a. cells die at increasingly greater rates b. only older cells die in a culture c. cells in a culture die at a constant rate d. upon contact with the control agent, all cells die at one time e. cells become metabolically inactive but are never killed
C
Which of the following DNA sequences is complementary to 5' TAGAC 3'? a. 5' TAGAC 3' b. 5' ATCTG 3' c. 5' GTCTA 3' d. 5' CAGAT 3' e. none of the above
C
Which of the following is officially accepted as a sterilant and high-level disinfectant? a. benzalkonium chloride b. silver nitrate c. glutaraldehyde d. triclosan e. cresol
C
Which of the following types of agents targets protein conformation? a. Detergents b. Ultraviolet light c. Alcohol d. Hydrogen peroxide e. Crystal violet
C
Addition or deletion of bases that changes the reading of mRNA codons a. spontaneous mutation b. induced mutation c. substitution mutation d. frameshift mutation
D
Historically, which of the following was instilled into the eyes of newborn infants to prevent gonococcal infections? a. triclosan b. formaldehyde c. phenol d. silver nitrate e. mercurochrome
D
In eukaryotic cells, what cellular structure is composed of a neatly packaged DNA molecule? a. gene b. genome c. genotype d. chromosome e. histone
D
Sterilization is achieved by: a. flash pasteurization b. hot water c. boiling water d. steam autoclave e. all of the choices are correct
D
The process of using a cleansing technique to mechanically remove and reduce microorganisms and debris to safe levels is: a. disinfection b. sterilization c. antisepsis d. sanitization e. degermation
D
Which is mismatched? a. Sodium hypochlorite - chlorine b. Iodophor - iodine c. Benzalkonium chloride - quaternary ammonium compound d. Merthiolate - silver e. Formalin - formaldehyde
D
Which of the following is NOT a result of transposon activity in bacteria? a. changes in traits such as colony morphology, pigmentation, and antigenic characteristics b. replacement of damaged DNA c. transfer of drug resistance in bacteria d. correction of ultraviolet radiation mutations
D
Which of the following microbial forms have the highest resistance to physical and chemical controls? a. naked viruses b. protozoan cysts c. fungal spores d. bacterial endospores e. yeast
D
Which of the following types of control agents would be used to achieve sterility? a. virucide b. bactericide c. germicide d. sporicide e. fungicide
D
Alcohols: a. denature proteins when in a 50-95% solution. b. are used to disinfect items by soaking. c. are skin degerming agents. d. at 50% or higher concentrations dissolve cell membrane lipids. e. All of the choices are correct.
E
All of the following are benefits of food irradiation, except: a. it can kill bacterial pathogens on the food. b. it can kill insects on the food. c. it can inhibit the sprouting of white potatoes. d. it can reduce the number of food-borne deaths each year. e. it makes the food less nutritious.
E
All of the following are phenols or phenolics, except: a. lysol b. hexachlorophene c. triclosan d. cresols e. chloramines
E
All the following are correct about detergents, except: a. they are polar molecules that act as surfactants. b. the most effective ones are positively charged. c. in low concentrations they are bacteriostatic. d. they are ineffective against the tuberculosis bacteria. e. they are active in the presence of organic matter.
E
Electrons are ejected from atoms in cells when organisms are exposed to: a. dessication b. ultraviolet light c. ethyl alcohol d. hydrogen peroxide e. gamma rays and X-rays
E
Endospores can be killed by: a. dry heat at 170° C for 2 hours. b. incineration. c. glutaraldehyde for 3 or more hours. d. ethylene oxide for 3 or more hours. e. all of the choices are correct
E
Physical agents for controlling microbial growth include all of the following, except: a. ultraviolet radiation b. boiling water c. HEPA filters d. pasteurization e. hydrogen peroxide
E
Scrubbing or immersing the skin in chemicals to reduce the numbers of microbes on the skin is: a. disinfection b. sterilization c. antisepsis d. sanitization e. degermation
E
Which of the following is NOT a nitrogen base found in DNA? a. adenine b. cytosine c. guanine d. thymine e. uracil
E
Which of the following is not used as an antiseptic? a. iodophor b. chlorhexidine c. 3% hydrogen peroxide d. merthiolate e. aqueous glutaraldehyde
E
Which of the following items are typically irradiated in order to kill microbes? a. ground beef and other meat and poultry b. human tissues such as heart valves and skin c. operating room air d. surgical gloves e. all of the choices are correct
E
Which of these metals have antimicrobial properties associated with them? a. silver b. gold c. tin d. aluminum e. both A and B are correct
E
_____ is a halogen used in gaseous and liquid form for large scale disinfection of drinking water and sewage.
chlorine
Some microbial control agents are able to _____ cell proteins by breaking bonds that maintain the native state, three-dimensional configuration of the proteins.
denature
